The present application relates generally to the field of DC to AC power supplies, and more specifically to the field of multi-stage inverter power supplies.
Many applications, such as hydrogen fuel-cell vehicles utilize low voltage power sources. In the case of a hydrogen fuel-cell vehicle the power source is the fuel-cell, however, other applications could use any number of other low voltage DC power sources such as a battery. These power sources often have a limited time at which they can retain their original maximum charge, and after that time the maximum charge which can be retained decreases steadily over time.
Current switching inverter technology uses single phase switching inverters where the DC power is directly converted into AC power for use with the vehicle or other system. The direct conversion results in a system where the amplitude of the AC output is directly proportional to the amplitude of the DC input at all times. In order to utilize a DC power source for longer, it is necessary to have a means of ensuring that the output voltage of the switching inverter phase has a constant peak to peak value, despite a decrease in output potential of the DC power source.
Current inverting electric power supplies do not include ways to boost the voltage of a power supply whose maximum charge has decreased due to time or other factors, and as such the power supplies utilized in conjunction with the inverting electric power supplies must be replaced frequently.
An additional side affect of current switching inverter technology is a large amount of electric noise which is introduced into the AC signal as a result of the switching. Maintaining the output signal at a constant frequency results in a large noise spike at that frequency. The presence of electrical noise in the AC signal output can interfere with the functions of a vehicle system, or any other system.